US3079880A - Apparatus for guiding a workpiece under the needle of a sewing machine - Google Patents

Apparatus for guiding a workpiece under the needle of a sewing machine Download PDF

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US3079880A
US3079880A US71641A US7164160A US3079880A US 3079880 A US3079880 A US 3079880A US 71641 A US71641 A US 71641A US 7164160 A US7164160 A US 7164160A US 3079880 A US3079880 A US 3079880A
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needle
shaft
driven shaft
carriage
cam
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US71641A
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Bihaly Lajos
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Trubenised Co
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Trubenised Co
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    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B21/00—Sewing machines with devices for automatically controlling movement of work-carrier relative to stitch-forming mechanism in order to obtain particular configuration of seam, e.g. programme-controlled for sewing collars, for attaching pockets

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  • This invention relates to apparatus for guiding a workpiece under the needle of a sewing machine and, more particularly, to such apparatus of the kind in which the workpiece is automatically guided along a stitching line of predetermined form.
  • a supporting carriage for a frame holding the workpiece is provided with first control means adapted to effect movement in a first sense of the carriage in a plane normal to the needle of the sewing machine and second control means adapted to eiiect movement of the carriage in the said plane in a second sense at or substantially at right angles to the first sense.
  • Driving means for the control means in that known form of apparatus comprise a constant speed electric motor having associated therewith a spring biassed friction clutch mechanism of known form which may be actuated so as to transmit the drive of the electric motor through suitable gearing both to the main shaft of the sewing machine head and a further drive shaft for operating the first and second control means.
  • a constant speed motor in the known form of apparatus described above gives rise to certain operational difiiculties particularly when it is desired to stitch along a predetermined stitching line which includes a discontinuity, the term discontinuity being used herein to embrace such things as the ends of a stitching line or an abrupt change of direction in the line of stitching.
  • the invention includes apparatus for automatically guiding a workpiece under the needle of a sewing machine along a line of stitching of predetermined form including a discontinuity, comp-rising a workpiece supporting carriage, first control means adapted to efiect movement of the carriage in a plane normal or substantially normal to the needle of the sewing machine in a first sense, second control means adapted to effect move ment of the carriage in the said plane in a second sense normal or substantially normal to the first sense, and driving means adapted to eflect movement at least of the first and second control means at a first relatively low rate over a length of the line of stitching including the discontinuity and at a second relatively high rate over can be avoided.
  • Another object of this invention is to provide an automatic sewing machine of the character described wherein a workpiece supporting carriage, movable in a plane substantially normal to the endwise reciprocating needle on the machine, carries a workpiece under the needle and along a defined path in said plane that causes a stitching line of predetermined configuration to be formed in the workpiece, wherein the carriage advances the workpiece at a high speed through the greater portion of the length of the path but moves the workpiece at a lower speed in predetermined portions of the path where discontinuities are to be made in the stitching line or where for other reasons slower motion of the workpiece relative to the needle is required, and wherein the rate of needle reciprocation is so controlled that needle speed is at all times coordinated with the speed at which the workpiece is advancing along its path.
  • Another object of this invention is to provide an automatic sewing machine which achieves the above stated objectives and which also includes means for automatically insuring that the needle of the machine is stopped in a raised position at the finish end of each stitching line.
  • FIGURE 1 a perspective drawing of an automatic ewing machine to which the invention is applied;
  • FlGURE 2 is a perspective drawing of the mechanism of the sewing machine shown in FIGURE 1, certain of the parts being shown of simplified construction and displaced s mewhat in order to clarify the arrangement;
  • FEGURE 3 is a side elevation, partly in section, of a two-motor driving assembly indicated in FIGURE 2;
  • FIGURE 4 is a plan view of a stop latch mechanism indicated FIGURE 2;
  • FEGURE 5 is a front elevation of a cam assembly indicated in FIGURE 2;
  • FIGURES 6, 7 and 8 are side elevations respectively of three disc cams shown in FIGURE
  • FIGURE 9 is a front elevation of an interlock mechan'ism indicated in FIGURE 2;
  • FIGURE 10 is an electrical circuit diagranrfor the automatic sewing machine shown in the preceding figures.
  • the function of the apparatus is to guide a workpiece under the needle of a sewing machine so that the workpiece moves along a stitching line of predetermined form including a discontinuity; and the apparatus is utilised'in the massproduction of mens shirt collars of the one piece kind for the preliminary sewing of the interlining' to the front and rear fabric plies of the collar prior to the turning of the collar in known manner to locate the interlining etween the front and rear plies.
  • the apparatus includes a sewing machine head' 1- having a sewing needle 3, a needle driving main shaft sprocket 5 and a bobbin 7.
  • the sewing machine head 1 is mounted on a cabinet 9m and on which" A carriage are mounted the other parts of the apparatus.
  • 11" on whichis detachably mounted a workpiece supporting frame 13, is mounted'for sliding movement from left t'o'right, as viewed'inthe direction indicated by the arrow A in FIGURE 1, on'two horizontal parallel rods 15, and
  • these two rods are secured at their ends to sleeves 17 helical groove 23 constituting the cam track and adapted to'control movement of the carriage 11 ina plane normal to-the axisbf the sewing machine needle 3 and in a direction from left to-right of the head 1.
  • the second control means include, mounted on the cam shaft 19, a disc cam 25' formed with'aperipheral cam tracli (not shown) adapted to controlmovement of the carriage 11 in the same planenormal to the sewing machine needle axis as the first control means but in adirection from front to
  • the first control means includes a pin 29 engaged in the helical groove 23 and coupled to the carriage 11- through a mechanical linkage indicated generally by 31, while the second control means includes a pin 39 engaged in the cam track in disc cam 25 and coupled to the sleeves 17" through a mechanical linkage indicated generally by 41.
  • the apparatus described above is described in greater detail in the specification of our United Kingdom Patent No. 745,474, which also includes a description of the operation of the apparatus.
  • Driving means adapted to elfect movement of the cam.
  • shaft 19' and, therefore, of the cylindrical cam 21 and the disc cam 25 of the first and second control means include a main electric motor 51 disposed with its axis upright and an auxiliary motor 53 disposed with its axis hori zontal.
  • auxiliary motor 53 disposed with its axis hori zontal.
  • FIGURE 3 On the output shaft 55 of the motor 51 is mounted a flywheel 57, through the intermediary of an output member 59 locked to the shaft 55 by a key 61 and locked to the flywheel by a key 63.
  • Output member 59 is supported in a thrust resisting'ball bearing 65 carried by an end plate 67 secured to the motor housing, and has mounted in it a bushing 69 coaxial with the shaft 55.
  • the flywheel 157 thus rotates with the shaft 55' and constitutes a driving member of a clutch mechanism described below.
  • Mounted on the end plate 67 is a housing 71 to an upper part of which is bolted the housing of the auxiliary motor $3.
  • Through housing 71 extends a vertical driven shaft 73 coaxial with the output shaft 55, supported at its upper 4 end in a journal ball bearing 75 and at its lower end in. the bushing 69.
  • a V-belt pulley 77 is mounted on the shaft 73 and is slidably keyed to that shaft by a key 79.
  • a depending boss of the pulley is formed with a waisted portion encircled by a clutch withdrawal ring 81 engaged at two diametrically opposite points by pins, such as the pin 83, carried by a forked end of a clutch lever 85 pivotally mounted on. a pin'87 carried on the housing 71,
  • This depending boss is formed, below the ring 531, as a plate 89 having a central recess 89A to ic.V an annular clutch bearing surface 898 arranged to engage, when the pulley 77 is forced downwardly, an annular insert 57A of friction material such as cork mounted in the upper face of the flywheel 57.
  • a spring 93 actlow.
  • the end of the clutchlever 85 remote from the pulley 77 is provided with an'adjustable stop 101 which bears against the upper end of a vertical armature rod lll3 A of an electro-magnet 103, energisation of which effects upward movement of the armature rod 103A and thereby rocking of the lever 85 about its pivot pin 87 against the action of the biasing spring 93 with the result that-the pulley 77 is disengaged from the driving member 99- and is brought into operative engagement with the flywheel 57'.
  • a wormwheel member 105 Rotatably mounted on the part of shaft 73 which lies above the pulley 77 is a wormwheel member 105 formed at its lower end with the driving member 99 and having'a wormwheel'1tl7 mounted on it and locked against rotation on it bya key 109.
  • Above the wormwheel 1(97 the'ruemher 105 is provided with a thrust resisting ball bearing 11 1' acting between the wormwheel 107 and the upper end of the housing 71.
  • This wormwheel is engaged with a worm gear 113 provided on the horizontally extending output shaft 115 of the auxiliary motor 53.
  • the free end of that shaft 115 is suitably supported in the housing 71.
  • the upper end of the shaft 73 is continued upwardly above the housing 71- and is utilised as a bobbin winder shaft in well known manner.
  • the main electric motor 51 is a /3 horsepower motor having an output shaft speed of 1440 r.p.rn.
  • the auxiliary motor 53 is a horsepower motor having an output shaft speed of 2850 r.p.m., these speeds being nominal speeds.
  • the speed reduction effected by the worm gear 113' and the wormwheel 197 is 24:1, so that while the speed of the flywheel 57 is 1440 r.p.m., that of the driving member 99 is only about 119 rpm.
  • the invention comprehends the use of a single motor or prime mover to afford different driving speeds for the pulley '77.
  • dual speed operation of the pulley may be eiiected by utilising the shaft of the single motor to drive an auxiliary shaft which is provided with a clutch device for driving a further shaft carrying a worm gear which is in mesh with the worrnwheel on the pul ey shaft 73.
  • the pulley 77 is arranged to drive by means of a V-belt 121 a further pulley 123 which is keyed to an upright shaft 125 provided above the pulley 123 with a bevel gear 127 and below the pulley with a worm gear 129.
  • Bevel gear 127 is in mesh with a bevel gear 131 mounted on a horizontal shaft 133 on which is keyed a chain sprocket 135.
  • a chain 137 coupics the chain sprocket 13-5 to the needle driving sprocket 5. It will be appreciated that this sprocket 5 drives the main shaft in the sewing machine head, and drives, in addition to the needle 3, the shuttle located below the needle.
  • the worm gear 129 is in mesh with a worm wheel 139 keyed to a shaft 141 extending laterally of the machine and on which is keyed a further bevel gear 143 in mesh with a bevel gear 145 provided on the rearward end of a forwardly and downwardly extending propeller shaft 147.
  • the shaft 147 enters a gear box 14a in which a bevel gear secured to the shaft is in mesh with another bevel gear carried on the horizontally disposed cam shaft 19.
  • a stop latch (see FIGURE 4) in the form of a disc 151 having a radially outwardly extending projection 151A adapted to engage a detent 153 pivotally mounted on a fixed pin 154 together with a member 135 biassed by a spring 157 into contact with the periphery of the disc 151 and arranged to engage the substantially radial face of the projection 151A opposite to that engaged by the detent 153, and thereby to limit rebound of the projection upon engagement wtih the detent 153.
  • the detent 153 is formed with a lug 161 provided with a pin 153 by which the detent is coupled to an end of a stop latch control rod 165.
  • the stop latch control rod is adapted to be actuated by a foot pedal of the machine.
  • each of these disc cams is formed with a peripheral recess 183A, 1333 or 3133C having a radially inwardly extending leading edge EEESAX, or 183C); a circumfe entially extending intermediate surface li flAY, 13332 or lhfiCY, and outwardly and rearwardly inclined trm'ling edge or 183C711.
  • leading edge S-BAX of the recess 133A in the first disc cam 133A is disposed angularly in advance of leading edge ldSCX of the recess 183C of the third disc cam 131C by an amount determined by the number of stitches it is required to perform by the auxiliary motor 53 at the end of the line of stitching, whilst the leading edge 1533K of the recess of the second disc cam 1332- is disposed angularly in the rear of the leading edge ESECX of th recess 133C of the third disc cam 181C by an amount dependent upon the number of st tches which the auxiliary motor 53 is required to perform at the begin ing of the line.
  • the recesses of the three disc cams 181A, 1318 and 1816 are respectively adapted to be engaged by three pivotally mounted lever latches Ill-35A, 1853 and 155C.
  • the lever latches l$A and 1853 associated with the first disc cam 181A and the second disc cam 181B are spring biassed towards contact with their associated disc cams and are adapted in their movements into and out of their .ssociated recesses 183A and 18313 to operate respective microswitches 187 and 189.
  • the pivotally mounted lever latch 1856 is pivoted between its ends and is adapted upon rotation thereof to cause rotation of an integral arm dd-CX which is connected by a pivotal connection 191 to a connecting rod 193 itself pivotally connected near the rear of the machine to the stop latch control rod 165 (see FEGURE 4) through a bell crank lever 1%.
  • the end of the lever latch C which is remote from the disc cam ldlC is linked with a left foot pedal 197 of two foot pedals 197, 199 provided at the front of the apparatus (see Fl -URES l and 2).
  • a vertical rod Zill connected at its lower end to the foot pedal 197 has a hooked upper end 2531A, the free end of which is vertically slotted and the lever latch sliding vertically in that slot.
  • FIGURE 9 shows a mechanical interlock device indicated generally in FIG- Uilc 2 and which serves upon depressing the left foot p oal l7 to cause the right foot pedal 19% .to be raised, whereby the follower of the cylindrical cam is returned to the cam track thereof whilst the foot of the sewing machine head is lowered onto a workpiece.
  • the foot pedal 197 is connected by a vertical rod 215 to a lever 23.7 mounted on a horizontal pivot pin 219 and swingable between fixed stops 221 but biassed upwardly by a spring 223.
  • the foot pedal 199 is connected by a vertical rod to a lever 2-27 mounted on a horizontal pivot pin 229 and swingable between fixed stops 231 but biassed in an anticlockwise direction by the spring 233.
  • the top edge ail-7A of the lever 227 is arcuate about the pin 229 and is shaped to provide two oppositely facing abutments 235
  • a first pawl 239 mounted on a pivot pin 24% is b assed by a spring 241i into contact with the top edge 2327A and is connected by a rod 243 which permits lost motion to the lever E17.
  • the spring 241 will maintain the pawl in contact with the edge 227A unless the left pedal 19'?
  • a second pawl 245 mounted on a pivot pin 246 is biassed by a spring 247 away from the top edge 227A against a stop 249, but is connected to the armature 251A of an electromaguet 251 which, when energised, moves the pawl 245 against the efiect of the spring 247 into engagement with the edge 227A.
  • microswitch 253 is engageable by a stud 256 mounted on the lever 227 in such a manner that when the right pedal 199 is in its up position the microswitch is operated. It will be seen that, if the electromagnet 251 is energised when the parts are in the position shown, the pawl 245 will engage the abutment 237 and prevent depression of the right pedal 199. Further, when the right pedal 199 has been depressed, the pawl 239 will engage the abutment 235, and prevent upward movement of the right pedal 199 until the left pedal 197 has been pressed to release the pawl 239. a
  • the stop latch detent 153 releases the projection 151A on the disc 151 (see FIGURE 4) to free the stop latch and sewing of the workpiece commences under the influence of the auxiliary motor for a predetermined number of stitches whereupon the sewing operation automatically is brought under the control of the main motor 51 and remains under the control of this motor until a predetermined number of stitches before the end of the stitching line, at which instant the sewing operation is again automatically brought under the control of the auxiliary motor 53 and sewing proceeds to the end of the stitching line under the control of this motor.
  • the auxiliary motor 53 is stopped with the needle of the sewing machine out of the workpiece.
  • the right foot pedal 199 is then depressed once more and the frame carrying the workpiece is removed.
  • the carriage 11 can then be' returned to its extreme left position for attachment of a further workpiece holding frame.
  • a lever 255 is mounted on a pin 257 carried'by the detent 153 and is biassed by a spring 259 towards the shaft 125.
  • a pin 262 mounted on the disc 151 can cause the lever 255 to rock against the biassing force of spring 259 to engage the operating member of a microswitch 263.
  • the contacts of switch 263 are held open when the parts are in the position shown in FIG- URE 4.
  • FIGURE 10 The interconnection of the various motors and micro switches is shown in. FIGURE 10.
  • V In series with the stop latch microswitch 263' is the microswitch 253 of the interlock device between the two foot pedals, the switch 253 being normally open but being closed upon depression of the left foot pedal 197.
  • a coil of a relay 265 for operating the auxiliary motor 53 relay 265 being referred to hereinafter as the auxiliary motor relay 265.
  • a two posit-ion manually operated emergency switch 267 having normal .and emergency dispositions indicated by N and B respectively, is also provided of which the normal contacts N are arranged in series with the stop latch microswitch 263.
  • branch 1 comprising the stop latch microswitch 263, the auxiliary motor relay coil 265, the interlock microswitch 253 and the normal contacts N of the emergency switch is connected in parallel withzthe main motor 51 and with a starter 269 therefor, the latter being connected to the electrical mains supply 271 by way of a mains switch (not shown).
  • branch I Also connected in parallel with branch I is a branch comprising an emergency relay coil 273 and the emergency contacts E of the two position emergency switch 267, these latter contacts E being shunted by a pair of. contacts 273A of the emergency relay 273 in series with a pair of contacts 275A of a push-button reset switch 275. These contacts of the reset switch are biassed towards. a closed position thereof.
  • a series path comprising the auxiliary motor 53, a two position contact 277A of a clutch control relay 277 and a pair of contacts 265A of the auxiliary motor relay 265-.
  • the two position contact 277A of the clutch control. relay 265 is biassed to a position when the coil of this relay is de-e .ergised, to provide a current path through the auxiliary motor 53 and the contacts including contact 277A of the auxiliary motor relay in series therewith.
  • Three further branches. connected in parallel with branch I each including the pair of contacts 265A are provided. These comprise first a branch in which the auxiliary motor relay contacts 265A are connected in series with the coil of the interlock electromagnet 251, energisation of which serves to maintain the right foot pedal 199 in its upper interlocked position as has been described above in connection with FIGURE 9. Secondly, the contacts 265A are connected in series with the following elements: a pair of contacts 273B associated with the coil of the emergency relay 273,, the microswitch 189 actuated by the lever latch B of the second disc cam 1818, and the coil of the clutch control relay 277. Thirdly, the contacts 265A are connected in series with the following elements to form a branch connected in parallel with the branch I: the clutch control relay coil 277, the
  • microswitch 187 actuated by the lever latch 185A of the first disc cam 181A, and the two-position contact 277A of the clutch control relay 277. These latter contacts of the two-position contact of the clutch control relay are adapted to close upon the energisation of the clutch control relay coil 277. Shunting the microswitches 187 and 189 is a pair of contacts 275B of the reset switch 275 and these contacts are biassed to the open position thereof.
  • the coil of the electromagnet 103 controlling the operation of the clutch mechanism associated with the main motor 5 1 is connected in series with a pair of contacts 2778 of the clutch control relay 277 across the mains supply and further connected across the mains supply is a primary winding 2791 of a transformer 279 in the secondary circuit of which is provided a light bulb 281'for illuminating the needle of the sewing machine head.
  • the left and right foot pedals 197 and 199 are both in their uppermost positions and the mains switch is operated to provide a supply of current for the main motor 51.
  • the right foot pedal 199 is then depressed with the result that the follower pin 29 of the cylindrical cam 21 is Withdrawn from its cam groove 23 and the foot on the sewing machine head is raised.
  • the carriage 11 of the machine is moved to its extreme left position and a frame supporting a workpiece is then attached to the carriage.
  • the left foot pedal 197 is then depressed and causes release of the stop latch (FIGURE 4) and re-enegagement of the follower pin 29 of the cylindrical cam 21 in its associated cam track groove 23.
  • Depressing the left foot pedal 197 also be releasing the right foot pedal lowers the foot of the sewing machine head onto the workpiece.
  • the lever latch 185A of the first disc cam 1811A is engaged in the circumferentially extending par-t 183AY of the recess 183 in that cam
  • the lever latch 1855 of the second disc cam 181B is engaged with the periphery of the second disc cam 181B a few degrees in advance of the recess 1833 in that earn whilst the lever latch 185C of the third disc cam 131C is engaged within the recess 133C of that cam adjacent the radially inwardly extending leadin edge 183CX thereof.
  • the interlock microswitch 253 closes and the stop latch microswitch 263 is also closed, with the result that the auxiliary motor relay 265' is energised and the pair of contacts 265A associated therewith close.
  • the auxiliary motor 55 is switched on and sewing commences at the lower speed determined by the auxiliary motor and its associated gearing. Sewing at the lower speed proceeds until the cam shaft 19 has rotated through the few degrees necessary to cause the lever latch 185B associated with the second disc cam 1313 to drop into the recess $83 of that cam.
  • lever latch 135A associated with the first disc cam 181A rides up the rear trailing edge 183AZ of the recess 183A in that cam, causing the contacts of the microswitch 187 to close slowly whilst the lever latch 185B associated with the second disc cam 181B subsequently rides up the trailing edge ISSBZ in that cam causing the contacts of the microswitch 139 associated with that cam to open slowly, but the result of this is that although energisation of the clutch control relay 277 by way of the microswitch 18? is interrupted, energisation of this relay coil 277 is maintained as a result of the closure of the microswitch 137 associated with the first disc cam 131A.
  • the energisation of the clutch control relay causes closure of the contacts in series with the coil of the electromagnet Hi3 which operates the clutch mechanism of the main motor 51 and the drive of the main motor is thereby transmitted both to the sewing machine head 1 and to the cam shaft 19 and sewing, therefore, continues at the higher speed governed by the main motor.
  • the lever latch 135A associated with the first disc cam 181A drops into its associated recess 183A and the contacts of the microswitch 187 associated with that cam open causing de-energisation of the clutch control relay 277 with opening of the contacts 277A associated with that relay and consequent de-energisation of the electromagnet 193 which actuates the clutch mechanism.
  • the drive of the main motor 51 is thus disconnected both from the sewing machine head 1 and from the cam shaft 19.
  • the two-position contacts 277A in series with the microswitch 187 are tie-energised and the two-position contact 277A is repositioned so as to switch on the auxiliary motor 53 so that over the last few stitches of the predetermined stitching line sewing proceeds at the lower rate governed by the auxiliary motor 53.
  • the lever latch 185C associated with the third disc C21 181C drops into its associated recess 183C with the result that the stop latch (see FiGURE 4) is operated, the detent 1S3 stopping continued movement of the disc 15 by engaging the leading face of the projection 151A and the member 155 preventing any rebound movement.
  • the emergency switch 267 is placed in the emergency position to contact the terminal E.
  • This causes de-energisation of the auxiliary motor relay coil 2&5, energisation of the emergency relay 2'73, closure of the contacts 273A in series with the coil of relay 273 and opening of the contacts 2738 in series with the contacts of the microswitch 189 associated with the second disc cam 1813.
  • Both the auxiliary motor 53 and the clutch electromagnet 163 are therefore de-energised and the carriage ll of the apparatus is brought to rest and the obstruction can then be cleared
  • the emergency switch is then restored to its normal position with the result that the auxiliary motor relay 265 is energised and sewing recommences under the influence or" the auxiliary motor 53.
  • the reset button 2'75 is pressed causing de-energisation of the emergency relay 273 and closure of the emergency relay contacts 2738 in series with the contacts of the microswitch 7.89 associated with the second disc cam 1813.
  • the pressing of the reset switch button 275 causes energisation of the clutch control relay 277, depending upon the positions or" the latch levers A, 1858 and 185C of the three disc cams 181A, 1813 and 131C, either by way of the contacts of the microswitch 139 associated with the second disc cam 1813 or by way of the contacts of the microswitch 13? associated with the first disc cam 181A in series with the contacts 2733 of the emergency relay 273, which are biassed to closure thereof.
  • the apparatus described enables sewing of a predetermined stitching line to be carried out in three stages, namely, a first stage in which sewing is conducted over an initial portion of the stitching line at a lower speed governed by the auxiliary motor 53, a second stage during which sewing of an intermediate portion of the stitching line is conducted at a higher speed governed by the main motor 51 of the apparatus, and a third stage in which a final portion or" the stitching line is conducted at the lower speed determined by the auxiliary motor 53.
  • the invention renders feasible the attachment of an interiining ply to the plies of a one-piece collar without the use of loops at the points of the collar as described in United Kingdom patent specification No. 709,642.
  • the invention provides the possibility of applying the peripheral decorative stitching to a one-pi ce collar after the turning of the collar to bring the intcrlining thereof between the front and rear plies of the collar.
  • an electro-magnetic clutch in the drive from the motors 51 and 53 to the main shaft of the sewing machine head 1, for example, at the sprocket 5 or the sprocket 135, the further possibility is afforded of forming a predetermined line of stitching including a break, that is to say a section in which no stitches are made.
  • the speed at which stitching can be carried out under the influence of the main driving motor 51 can be increased. Also, sewing ripples at the commencement of stitching are avoided. Further, the invention enables stitching to be stopped precisely at the end of the stitching line with the needle out of the workpiece, so that no manual operation of the sewing machine needle by the operator of the apparatus is required. Breakages of thread caused by the sudden stopping of theapparatus at the end of thestitching line are also avoided.
  • the apparatus of the present invention facilitates mass production of articles for use in the garment industry, for example, shirt collars or cuffs, to be effected atia higher rate than has been the case hitherto.
  • (G) means comprising a manually operable actuator for causing the clutch device to couple the driven shaft with the first power shaft to initiate carriage movement and needle reciprocation at low speed;
  • (H) a clutch control comprising means connected with the driven shaft to be responsive to the position of angular displacement thereof and operatively associated with the clutch device for causing the clutch device to couple the driven shaft with the second power shaft for high speed operation of the carriage and needle in consequence of apredetermined rotational displacement of the driven shaft at low speed.
  • (G) clutch control means responsive to rotational displacement of the driven shaft and operatively associated with the clutch device (1) for causing the clutch device to couple the driven shaft with the first power shaft at times 12 when :the driven shaft is rotatably displaced by certain angles from its said rotational position, and (2) for fcausing the clutch device to couple the driven shaft with the second power shaft at times when the driven shaft is in other positions of rotational displacement from its said rotational position.
  • brake actuator means operatively associated with the detent brake means and responsive to rotational displaement of the driven shaft for engaging the detent brake means with the driven shaft whenever the driven shaft is brought to its said one rotational position;
  • camshaft means drivingly connected with the driven shaft for rotation at a speed which is in a predetermined ratio to the speed of the driven shaft;
  • (F) carriage actuating means drivingly connected with the driven shaft, for moving the carriage along the length of a predetermined path in its said plane of motion during each revolution of the camshaft means from a predetermined rotational position;
  • (H) clutch control means comprising cam follower means cooperating with said cam means and operatively associated with the clutch device (1) for coupling the driven shaft with the first power shaft during movement of the cam shaft means through predetermined portions of each revolution thereof out of its said predetermined rotational position, and
  • detent brake means releasably engageable with the driven shaft for stopping the same in a predetermined position of rotation at which the needle is 'raised;

Description

L. BIHALY APPARATUS FOR GUIDING A WORKPIECE UNDER March 5, 1963 THE NEEDLE OF A SEWING MACHINE Filed Nov. 25, 1960 INVENTOR L ajas .Evzha Zy B) A TTORN Y March 5, 1963 L. BIHALY 3,079,880
APPARATUS FOR GUIDING A WORKPIECE UNDER THE NEEDLE OF A SEWING MACHINE Filed NOV. 25, 1960 6 Sheets-Sheet 2 IN VEN TOR Laja s .EIzZ'LEZy A TTORNE) March 5, 1963 L. BlHALY APPARATUS FOR GUIDING A WORKPIECE UNDER THE NEEDLE OF A SEWING MACHINE 6 Sheets-Sheet 3 Filed Nov. 25, 1960 //V I/(E/VTOR BIZ-Lazy Lajus A TTORA/EY March 5, 1963 L. BIHALY 3,079,880
APPARATUS FOR GUIDING A WORKPIECE UNDER THE NEEDLE OF A SEWING MACHINE Filed Nov. 25, 1960 6 Sheets-Sheet 4 Fig.5.
lNVENTOR Lajos .BzhaZy A TTORNEY March 1963 L. BIHALY 3,079,880
- APPARATUS FOR GUIDING A WORKPIECE UNDER THE NEEDLE OF A SEWING MACHINE 6 Sheets-Sheet 5 Filed Nov. 25. 1960 ATTORNE) March 5, 1963 BIHALY 3,079,880
APPARATUS FOR GL IDING A WORKPIECE UNDER THE NEEDLE OF A SEWING MACHINE Filed Nov. 25, 1960 6 Sheets-Sheet 6 A 275 273 273A 1 5275A 25/ FY2651; 1v
' 2&7
IN VENTOE Lajns 317157) B) A TTOR/VEY non a womrrrscn NEEIBLE or A Macrame (llaims This invention relates to apparatus for guiding a workpiece under the needle of a sewing machine and, more particularly, to such apparatus of the kind in which the workpiece is automatically guided along a stitching line of predetermined form. In one known form of apparatus or" the kind specified a supporting carriage for a frame holding the workpiece is provided with first control means adapted to effect movement in a first sense of the carriage in a plane normal to the needle of the sewing machine and second control means adapted to eiiect movement of the carriage in the said plane in a second sense at or substantially at right angles to the first sense. Driving means for the control means in that known form of apparatus comprise a constant speed electric motor having associated therewith a spring biassed friction clutch mechanism of known form which may be actuated so as to transmit the drive of the electric motor through suitable gearing both to the main shaft of the sewing machine head and a further drive shaft for operating the first and second control means. The employment of a constant speed motor in the known form of apparatus described above gives rise to certain operational difiiculties particularly when it is desired to stitch along a predetermined stitching line which includes a discontinuity, the term discontinuity being used herein to embrace such things as the ends of a stitching line or an abrupt change of direction in the line of stitching. One operational difiiculty arising from the use of a constant speed motor in previously known forms of apparatus is that starting of the motor at the beginning of the stitching line creates a high initial acceleration of the moving parts which, in the case of a workpiece comprising a plurality of superposed textile fabric plies, may give rise to the formation of a sewing ripple.
Also, with the known arrangement described above, it is difficult to ensure that stitching will be terminated Xactly at the end of the stitching line. This fact has led "to the practice of providing means whereby the electric motor is disengaged a few, say 5 or 6, stitches before the end of the stitching line and the inertia of the moving parts of the apparatus is utilised to effect stitching of the end portion of the stitching line. One important defect or" this technique is that the tightness of coaoting moving parts of the apparatus and the viscosity of oil in the gearbox containing the gearing of the drives to the sewing machine drive shaft and the drive shaft of the first and econd control means varies and may result in the inertia of the apparatus being insuificient to effect stitching of the selected number of stitches to bring the needle to the end of the stitching line. In this event, the operator of the apparatus has to operate the sewing head manually to perform the final stitch or stitches of the stitching line. Alterna ively, appreciable momentum of the moving parts may remain at the end of the stitching line, causing appreciable strains and wear upon sudden stopping of the drive. Further, the sudden stopping of the drive may cause breakage of the sewing thread. 7
It will be appreciated that these disadvantages adverse ly afiect the productive capacity of the known form of apparatus described above and it is, accordingly, one 'obiect of the present invention to provide an improved form of apparatus for guiding a workpiece under the hired rates haircarice needle of a sewing machine in which the said disadvantages can be largely, if not entirely, overcome and which is, accordingly, capable of operating at a higher rate of production than the known form of apparatus described.
The invention includes apparatus for automatically guiding a workpiece under the needle of a sewing machine along a line of stitching of predetermined form including a discontinuity, comp-rising a workpiece supporting carriage, first control means adapted to efiect movement of the carriage in a plane normal or substantially normal to the needle of the sewing machine in a first sense, second control means adapted to effect move ment of the carriage in the said plane in a second sense normal or substantially normal to the first sense, and driving means adapted to eflect movement at least of the first and second control means at a first relatively low rate over a length of the line of stitching including the discontinuity and at a second relatively high rate over can be avoided.
the remainder of the line of stitching.
Another object of this invention is to provide an automatic sewing machine of the character described wherein a workpiece supporting carriage, movable in a plane substantially normal to the endwise reciprocating needle on the machine, carries a workpiece under the needle and along a defined path in said plane that causes a stitching line of predetermined configuration to be formed in the workpiece, wherein the carriage advances the workpiece at a high speed through the greater portion of the length of the path but moves the workpiece at a lower speed in predetermined portions of the path where discontinuities are to be made in the stitching line or where for other reasons slower motion of the workpiece relative to the needle is required, and wherein the rate of needle reciprocation is so controlled that needle speed is at all times coordinated with the speed at which the workpiece is advancing along its path.
By providing an apparatus whereby the sewing rate and rate or" movement of the workpiece is reduced over a length of the stitching line including a discontinuity, it will be understood that the high initial acceleration of the moving parts and consequent sewing ripple occasioned thereby Similarly, by arranging for a reduced rate or" movement of the workpiece and the sewing machine needle at the end of the line of stitching, it is possible, because of the comparatively low inertia of the moving parts or the apparatus at this lower rate of movement, to ensure that the stitching is terminated instantaneously upon completion of the final stitch in the stitching line. Further, it has been found possible to speed up that part or" the stitching operation which is carried out at the higher speed thereby increasing the productive capacity or" the apparatus.
Another object of this invention is to provide an automatic sewing machine which achieves the above stated objectives and which also includes means for automatically insuring that the needle of the machine is stopped in a raised position at the finish end of each stitching line.
The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:
FIGURE 1 a perspective drawing of an automatic ewing machine to which the invention is applied;
FlGURE 2 is a perspective drawing of the mechanism of the sewing machine shown in FIGURE 1, certain of the parts being shown of simplified construction and displaced s mewhat in order to clarify the arrangement;
FEGURE 3 is a side elevation, partly in section, of a two-motor driving assembly indicated in FIGURE 2;
FIGURE 4 is a plan view of a stop latch mechanism indicated FIGURE 2;
FEGURE 5 is a front elevation of a cam assembly indicated in FIGURE 2;
rear of the needle.
3 FIGURES 6, 7 and 8 are side elevations respectively of three disc cams shown in FIGURE FIGURE 9 is a front elevation of an interlock mechan'ism indicated in FIGURE 2; and
FIGURE 10 is an electrical circuit diagranrfor the automatic sewing machine shown in the preceding figures;
Referring first to FIGURES l and 2, the function of the apparatus is to guide a workpiece under the needle of a sewing machine so that the workpiece moves along a stitching line of predetermined form including a discontinuity; and the apparatus is utilised'in the massproduction of mens shirt collars of the one piece kind for the preliminary sewing of the interlining' to the front and rear fabric plies of the collar prior to the turning of the collar in known manner to locate the interlining etween the front and rear plies. The apparatus includes a sewing machine head' 1- having a sewing needle 3, a needle driving main shaft sprocket 5 and a bobbin 7. The sewing machine head 1 is mounted on a cabinet 9m and on which" A carriage are mounted the other parts of the apparatus. 11", on whichis detachably mounted a workpiece supporting frame 13, is mounted'for sliding movement from left t'o'right, as viewed'inthe direction indicated by the arrow A in FIGURE 1, on'two horizontal parallel rods 15, and
these two rodsare secured at their ends to sleeves 17 helical groove 23 constituting the cam track and adapted to'control movement of the carriage 11 ina plane normal to-the axisbf the sewing machine needle 3 and in a direction from left to-right of the head 1. The second control means include, mounted on the cam shaft 19, a disc cam 25' formed with'aperipheral cam tracli (not shown) adapted to controlmovement of the carriage 11 in the same planenormal to the sewing machine needle axis as the first control means but in adirection from front to The first control means includes a pin 29 engaged in the helical groove 23 and coupled to the carriage 11- through a mechanical linkage indicated generally by 31, while the second control means includes a pin 39 engaged in the cam track in disc cam 25 and coupled to the sleeves 17" through a mechanical linkage indicated generally by 41. The apparatus described above is described in greater detail in the specification of our United Kingdom Patent No. 745,474, which also includes a description of the operation of the apparatus.
Driving means adapted to elfect movement of the cam. shaft 19' and, therefore, of the cylindrical cam 21 and the disc cam 25 of the first and second control means include a main electric motor 51 disposed with its axis upright and an auxiliary motor 53 disposed with its axis hori zontal. Although the arrangement of these two motors is indicated diagrammatically in FIGURE 2, the constructional detail of the mechanical interlinkage between these two motors is shown more clearly in FIGURE 3. On the output shaft 55 of the motor 51 is mounted a flywheel 57, through the intermediary of an output member 59 locked to the shaft 55 by a key 61 and locked to the flywheel by a key 63. Output member 59 is supported in a thrust resisting'ball bearing 65 carried by an end plate 67 secured to the motor housing, and has mounted in it a bushing 69 coaxial with the shaft 55. The flywheel 157 thus rotates with the shaft 55' and constitutes a driving member of a clutch mechanism described below. Mounted on the end plate 67 is a housing 71 to an upper part of which is bolted the housing of the auxiliary motor $3. Through housing 71 extends a vertical driven shaft 73 coaxial with the output shaft 55, supported at its upper 4 end in a journal ball bearing 75 and at its lower end in. the bushing 69. A V-belt pulley 77 is mounted on the shaft 73 and is slidably keyed to that shaft by a key 79.
A depending boss of the pulley is formed with a waisted portion encircled by a clutch withdrawal ring 81 engaged at two diametrically opposite points by pins, such as the pin 83, carried by a forked end of a clutch lever 85 pivotally mounted on. a pin'87 carried on the housing 71, This depending boss is formed, below the ring 531, as a plate 89 having a central recess 89A to ic.V an annular clutch bearing surface 898 arranged to engage, when the pulley 77 is forced downwardly, an annular insert 57A of friction material such as cork mounted in the upper face of the flywheel 57.
Normally; the pulley 77 is held out of engagement with the flywheeland to this end there is connected'wlth the clutch lever 85, on theside ofthe pivot pin re-;
mote fromthe-clrit'ch withdrawal ring, a spring 93 actlow. The end of the clutchlever 85 remote from the pulley 77 is provided with an'adjustable stop 101 which bears against the upper end of a vertical armature rod lll3 A of an electro-magnet 103, energisation of which effects upward movement of the armature rod 103A and thereby rocking of the lever 85 about its pivot pin 87 against the action of the biasing spring 93 with the result that-the pulley 77 is disengaged from the driving member 99- and is brought into operative engagement with the flywheel 57'.
Rotatably mounted on the part of shaft 73 which lies above the pulley 77 is a wormwheel member 105 formed at its lower end with the driving member 99 and having'a wormwheel'1tl7 mounted on it and locked against rotation on it bya key 109. Above the wormwheel 1(97 the'ruemher 105 is provided with a thrust resisting ball bearing 11 1' acting between the wormwheel 107 and the upper end of the housing 71. When the electro-magnet 163 is deenergised, the spring 93 causes the upper face of the pulley 7 7 to engage-the lower face of the ring 99A on the driving member 99 coupled to the wormwheel 107. This wormwheel is engaged with a worm gear 113 provided on the horizontally extending output shaft 115 of the auxiliary motor 53. The free end of that shaft 115 is suitably supported in the housing 71. The upper end of the shaft 73 is continued upwardly above the housing 71- and is utilised as a bobbin winder shaft in well known manner.
The main electric motor 51 is a /3 horsepower motor having an output shaft speed of 1440 r.p.rn., and the auxiliary motor 53 is a horsepower motor having an output shaft speed of 2850 r.p.m., these speeds being nominal speeds. The speed reduction effected by the worm gear 113' and the wormwheel 197 is 24:1, so that while the speed of the flywheel 57 is 1440 r.p.m., that of the driving member 99 is only about 119 rpm.
As will bedescribed hereinafter in greater detail, three conditions of operation are afiorded by the twin motor arrangement described above. First, with the electromagnet 103 ole-energised the pulley 771s coupled to the auxiliary motor 53, and with that motor de-energised, the pulley is at rest. This is the state whether the main motor 51 is energised or de-energised. Secondly, the auxiliary motor 53 can be switched on whilst the electro-magnet 193 is de-ene'rgised, so that the pulley is driven at the lower speed of 119 rpm. by the auxiliary moton. Thirdly, both the main motor 51 and the electro-magnet 103' can be energised, whereupon the pulley 77 is coupled through the flywheel 5-7 to. the main motor 51 and is driven at the higher speed of 1440 rpm.
Whilst in the apparatus described two motors have been utilised, the invention comprehends the use of a single motor or prime mover to afford different driving speeds for the pulley '77. Those skilled in the art will appreciate that with a single motor, dual speed operation of the pulley may be eiiected by utilising the shaft of the single motor to drive an auxiliary shaft which is provided with a clutch device for driving a further shaft carrying a worm gear which is in mesh with the worrnwheel on the pul ey shaft 73.
Referring now to FIGURE 2, the pulley 77 is arranged to drive by means of a V-belt 121 a further pulley 123 which is keyed to an upright shaft 125 provided above the pulley 123 with a bevel gear 127 and below the pulley with a worm gear 129. Bevel gear 127 is in mesh with a bevel gear 131 mounted on a horizontal shaft 133 on which is keyed a chain sprocket 135. A chain 137 coupics the chain sprocket 13-5 to the needle driving sprocket 5. It will be appreciated that this sprocket 5 drives the main shaft in the sewing machine head, and drives, in addition to the needle 3, the shuttle located below the needle. The worm gear 129 is in mesh with a worm wheel 139 keyed to a shaft 141 extending laterally of the machine and on which is keyed a further bevel gear 143 in mesh with a bevel gear 145 provided on the rearward end of a forwardly and downwardly extending propeller shaft 147. At its forward end, the shaft 147 enters a gear box 14a in which a bevel gear secured to the shaft is in mesh with another bevel gear carried on the horizontally disposed cam shaft 19.
Also carried on the shaft 125 of the further pulley 123 is a stop latch (see FIGURE 4) in the form of a disc 151 having a radially outwardly extending projection 151A adapted to engage a detent 153 pivotally mounted on a fixed pin 154 together with a member 135 biassed by a spring 157 into contact with the periphery of the disc 151 and arranged to engage the substantially radial face of the projection 151A opposite to that engaged by the detent 153, and thereby to limit rebound of the proiection upon engagement wtih the detent 153. The detent 153 is formed with a lug 161 provided with a pin 153 by which the detent is coupled to an end of a stop latch control rod 165. Movement of the rod 155 in a sense tending to release the detent from the projection 151A is opposed by a blessing spring 157 which is connected at one end thereof to the control rod 165 and is anchored at its other end to a fixed pin 369. As hereinafter described, the stop latch control rod is adapted to be actuated by a foot pedal of the machine.
The cam shaft 19 is continued through the gear box 149, on the side of the gear box remote from the cylin rical cam 21 an extension of the cam shaft has mounted on it an assembly of three disc cams 131A, i313, and 131C (se FlGURES 5 to 8). As indicated in FZGURES 6 .to 8, each of these disc cams is formed with a peripheral recess 183A, 1333 or 3133C having a radially inwardly extending leading edge EEESAX, or 183C); a circumfe entially extending intermediate surface li flAY, 13332 or lhfiCY, and outwardly and rearwardly inclined trm'ling edge or 183C711. The leading edge S-BAX of the recess 133A in the first disc cam 133A is disposed angularly in advance of leading edge ldSCX of the recess 183C of the third disc cam 131C by an amount determined by the number of stitches it is required to perform by the auxiliary motor 53 at the end of the line of stitching, whilst the leading edge 1533K of the recess of the second disc cam 1332- is disposed angularly in the rear of the leading edge ESECX of th recess 133C of the third disc cam 181C by an amount dependent upon the number of st tches which the auxiliary motor 53 is required to perform at the begin ing of the line.
The recesses of the three disc cams 181A, 1318 and 1816 are respectively adapted to be engaged by three pivotally mounted lever latches Ill-35A, 1853 and 155C. The lever latches l$A and 1853 associated with the first disc cam 181A and the second disc cam 181B are spring biassed towards contact with their associated disc cams and are adapted in their movements into and out of their .ssociated recesses 183A and 18313 to operate respective microswitches 187 and 189. The pivotally mounted lever latch 1856 is pivoted between its ends and is adapted upon rotation thereof to cause rotation of an integral arm dd-CX which is connected by a pivotal connection 191 to a connecting rod 193 itself pivotally connected near the rear of the machine to the stop latch control rod 165 (see FEGURE 4) through a bell crank lever 1%. The end of the lever latch C which is remote from the disc cam ldlC is linked with a left foot pedal 197 of two foot pedals 197, 199 provided at the front of the apparatus (see Fl -URES l and 2). A vertical rod Zill connected at its lower end to the foot pedal 197 has a hooked upper end 2531A, the free end of which is vertically slotted and the lever latch sliding vertically in that slot. The two parts of this free end, on either side of the slot, extend between two pins 2&3 provided on the lever latch 185C and extending right through that lever latch. A vertically extending bolt 2&5 extends down into the slot of the free end of the rod upper end 261A and permits adjustment of the position irthe travel of the foot pedal 19'! at which it becomes effective to release the latch 185C from the reces is By depressing this left foot pedal 197, the le r latch C is thus released and at the same time the stop latch control rod is moved to release the stop latch shown in FEGURE 4. Mounted on the disc cam 'ulC is a sector-like plate or arm Zll? mounted on a in which is adjacent to and parallel to the shaft 19, he arm 2%"! biassed by a spring 215 towards a stop When the arm 287 is butting against the stop 2&1, revents re-entry of the lever latch 385C into the recess L but if the disc cam 181C is then rotated through iticn in the direction indicated by the arrow 213, ,7 CY lever latch engages the leading edge ILA of arm 2%? and holds it against further rotation, o that i due course the lever latch can drop into its rile rig it foot pedal 199 is mechanically linked to the ollower pin 33 of the first control means and also to the presser foot of the sewing machine head i. Depressing or re rig t foot pedal 199 causes the follower pin 29 to no withdrawn from the helical groove 23 and causes the foot of the sewing machine head to be raised. The mechanism involved is not shown, but FIGURE 9 shows a mechanical interlock device indicated generally in FIG- Uilc 2 and which serves upon depressing the left foot p oal l7 to cause the right foot pedal 19% .to be raised, whereby the follower of the cylindrical cam is returned to the cam track thereof whilst the foot of the sewing machine head is lowered onto a workpiece. The foot pedal 197 is connected by a vertical rod 215 to a lever 23.7 mounted on a horizontal pivot pin 219 and swingable between fixed stops 221 but biassed upwardly by a spring 223. The foot pedal 199 is connected by a vertical rod to a lever 2-27 mounted on a horizontal pivot pin 229 and swingable between fixed stops 231 but biassed in an anticlockwise direction by the spring 233. The top edge ail-7A of the lever 227 is arcuate about the pin 229 and is shaped to provide two oppositely facing abutments 235 A first pawl 239 mounted on a pivot pin 24% is b assed by a spring 241i into contact with the top edge 2327A and is connected by a rod 243 which permits lost motion to the lever E17. Thus the spring 241 will maintain the pawl in contact with the edge 227A unless the left pedal 19'? is depressed, and even when that pedal is not depressed, the pawl can move against the'spring to engage the abutment 235. A second pawl 245 mounted on a pivot pin 246 is biassed by a spring 247 away from the top edge 227A against a stop 249, but is connected to the armature 251A of an electromaguet 251 which, when energised, moves the pawl 245 against the efiect of the spring 247 into engagement with the edge 227A. A
7 microswitch 253 is engageable by a stud 256 mounted on the lever 227 in such a manner that when the right pedal 199 is in its up position the microswitch is operated. It will be seen that, if the electromagnet 251 is energised when the parts are in the position shown, the pawl 245 will engage the abutment 237 and prevent depression of the right pedal 199. Further, when the right pedal 199 has been depressed, the pawl 239 will engage the abutment 235, and prevent upward movement of the right pedal 199 until the left pedal 197 has been pressed to release the pawl 239. a
The mechanical sequence of operations may now be described. On depressing the right foot pedal 199 the foot of the sewing head 1 is raised and the follower pin 29 of the cylindrical cam 21 is removed from the groove 23. The carriage 11 is now freed and can be manually moved to an extreme left. position where a frame holding workpiece is attached to the carriage. The left foot pedal 197 is then depressed and the mechanical interlock shown in FIGURE 9 releases the right pedal 199 so that it is raised by itsspring 233 and the foot of the sewing machine head is lowered onto the workpiece whilst the follower pin 29 of the cylindrical cam 21 is re-engaged in its cam groove 23. Upon this depression of the left foot pedal 197 the stop latch detent 153 releases the projection 151A on the disc 151 (see FIGURE 4) to free the stop latch and sewing of the workpiece commences under the influence of the auxiliary motor for a predetermined number of stitches whereupon the sewing operation automatically is brought under the control of the main motor 51 and remains under the control of this motor until a predetermined number of stitches before the end of the stitching line, at which instant the sewing operation is again automatically brought under the control of the auxiliary motor 53 and sewing proceeds to the end of the stitching line under the control of this motor. At the end of the stitching line the auxiliary motor 53 is stopped with the needle of the sewing machine out of the workpiece. The right foot pedal 199 is then depressed once more and the frame carrying the workpiece is removed. The carriage 11 can then be' returned to its extreme left position for attachment of a further workpiece holding frame.
The electrical apparatus required for performing the above sequence of events will now be described. As shown in FIGURE 4, a lever 255 is mounted on a pin 257 carried'by the detent 153 and is biassed by a spring 259 towards the shaft 125. As the disc 151 rotates in direc tion indicated by the arrow 261, a pin 262 mounted on the disc 151 can cause the lever 255 to rock against the biassing force of spring 259 to engage the operating member of a microswitch 263. The contacts of switch 263 are held open when the parts are in the position shown in FIG- URE 4.
The interconnection of the various motors and micro switches is shown in. FIGURE 10. V In series with the stop latch microswitch 263' is the microswitch 253 of the interlock device between the two foot pedals, the switch 253 being normally open but being closed upon depression of the left foot pedal 197. Also in series with these two microswitches is a coil of a relay 265 for operating the auxiliary motor 53, relay 265 being referred to hereinafter as the auxiliary motor relay 265. A two posit-ion manually operated emergency switch 267 having normal .and emergency dispositions indicated by N and B respectively, is also provided of which the normal contacts N are arranged in series with the stop latch microswitch 263.
The branch. hereinafter called branch 1, comprising the stop latch microswitch 263, the auxiliary motor relay coil 265, the interlock microswitch 253 and the normal contacts N of the emergency switch is connected in parallel withzthe main motor 51 and with a starter 269 therefor, the latter being connected to the electrical mains supply 271 by way of a mains switch (not shown). Also connected in parallel with branch I is a branch comprising an emergency relay coil 273 and the emergency contacts E of the two position emergency switch 267, these latter contacts E being shunted by a pair of. contacts 273A of the emergency relay 273 in series with a pair of contacts 275A of a push-button reset switch 275. These contacts of the reset switch are biassed towards. a closed position thereof.
Further connected in parallel with branch I is a series path comprising the auxiliary motor 53, a two position contact 277A of a clutch control relay 277 and a pair of contacts 265A of the auxiliary motor relay 265-. The two position contact 277A of the clutch control. relay 265 is biassed to a position when the coil of this relay is de-e .ergised, to provide a current path through the auxiliary motor 53 and the contacts including contact 277A of the auxiliary motor relay in series therewith.
Three further branches. connected in parallel with branch I each including the pair of contacts 265A are provided. These comprise first a branch in which the auxiliary motor relay contacts 265A are connected in series with the coil of the interlock electromagnet 251, energisation of which serves to maintain the right foot pedal 199 in its upper interlocked position as has been described above in connection with FIGURE 9. Secondly, the contacts 265A are connected in series with the following elements: a pair of contacts 273B associated with the coil of the emergency relay 273,, the microswitch 189 actuated by the lever latch B of the second disc cam 1818, and the coil of the clutch control relay 277. Thirdly, the contacts 265A are connected in series with the following elements to form a branch connected in parallel with the branch I: the clutch control relay coil 277, the
microswitch 187 actuated by the lever latch 185A of the first disc cam 181A, and the two-position contact 277A of the clutch control relay 277. These latter contacts of the two-position contact of the clutch control relay are adapted to close upon the energisation of the clutch control relay coil 277. Shunting the microswitches 187 and 189 is a pair of contacts 275B of the reset switch 275 and these contacts are biassed to the open position thereof.
The coil of the electromagnet 103 controlling the operation of the clutch mechanism associated with the main motor 5 1 is connected in series with a pair of contacts 2778 of the clutch control relay 277 across the mains supply and further connected across the mains supply is a primary winding 2791 of a transformer 279 in the secondary circuit of which is provided a light bulb 281'for illuminating the needle of the sewing machine head.
At the commencement of operation, the left and right foot pedals 197 and 199 are both in their uppermost positions and the mains switch is operated to provide a supply of current for the main motor 51. The right foot pedal 199 is then depressed with the result that the follower pin 29 of the cylindrical cam 21 is Withdrawn from its cam groove 23 and the foot on the sewing machine head is raised. The carriage 11 of the machine is moved to its extreme left position and a frame supporting a workpiece is then attached to the carriage. The left foot pedal 197 is then depressed and causes release of the stop latch (FIGURE 4) and re-enegagement of the follower pin 29 of the cylindrical cam 21 in its associated cam track groove 23. Depressing the left foot pedal 197 also be releasing the right foot pedal lowers the foot of the sewing machine head onto the workpiece. Immediately prior to the depressing of the left foot pedal 197 the lever latch 185A of the first disc cam 1811A is engaged in the circumferentially extending par-t 183AY of the recess 183 in that cam, the lever latch 1855 of the second disc cam 181B is engaged with the periphery of the second disc cam 181B a few degrees in advance of the recess 1833 in that earn whilst the lever latch 185C of the third disc cam 131C is engaged within the recess 133C of that cam adjacent the radially inwardly extending leadin edge 183CX thereof. Upon depressing the left foot pedal 197, the interlock microswitch 253 closes and the stop latch microswitch 263 is also closed, with the result that the auxiliary motor relay 265' is energised and the pair of contacts 265A associated therewith close. Upon closure of the contacts 265A, the auxiliary motor 55 is switched on and sewing commences at the lower speed determined by the auxiliary motor and its associated gearing. Sewing at the lower speed proceeds until the cam shaft 19 has rotated through the few degrees necessary to cause the lever latch 185B associated with the second disc cam 1313 to drop into the recess $83 of that cam. When this happens the contacts of the microswitch 89 actuated by that lever latch close and energisation of the clutch control relay coil 277 takes place by way of the branch comprising that coil, the contacts of re microswitch 139, the contacts 273A of the emergenc relay 273 which are biassed to a closed position and the closed contacts 265A of the auxiliary motor relay. Also, by virtue of the energisation of the clutch control relay coil 277, the two-position contact 277A in series with the microswitch 137 associated with the first disc cam 131A are moved to break the circuit of the auxiliary motor 53 and to close the contacts of the two-position contact277A in series with the microswitch 187. As rotation proceeds the lever latch 135A associated with the first disc cam 181A rides up the rear trailing edge 183AZ of the recess 183A in that cam, causing the contacts of the microswitch 187 to close slowly whilst the lever latch 185B associated with the second disc cam 181B subsequently rides up the trailing edge ISSBZ in that cam causing the contacts of the microswitch 139 associated with that cam to open slowly, but the result of this is that although energisation of the clutch control relay 277 by way of the microswitch 18? is interrupted, energisation of this relay coil 277 is maintained as a result of the closure of the microswitch 137 associated with the first disc cam 131A. The energisation of the clutch control relay causes closure of the contacts in series with the coil of the electromagnet Hi3 which operates the clutch mechanism of the main motor 51 and the drive of the main motor is thereby transmitted both to the sewing machine head 1 and to the cam shaft 19 and sewing, therefore, continues at the higher speed governed by the main motor.
Towards the end of a complete revolution of the cam shaft 19 and thus of the three disc cams 181A, 18113 and 1810, the lever latch 135A associated with the first disc cam 181A drops into its associated recess 183A and the contacts of the microswitch 187 associated with that cam open causing de-energisation of the clutch control relay 277 with opening of the contacts 277A associated with that relay and consequent de-energisation of the electromagnet 193 which actuates the clutch mechanism. The drive of the main motor 51 is thus disconnected both from the sewing machine head 1 and from the cam shaft 19. Also, the two-position contacts 277A in series with the microswitch 187 are tie-energised and the two-position contact 277A is repositioned so as to switch on the auxiliary motor 53 so that over the last few stitches of the predetermined stitching line sewing proceeds at the lower rate governed by the auxiliary motor 53. After a few further degrees of rotation of the three disc cams, the lever latch 185C associated with the third disc C21 181C drops into its associated recess 183C with the result that the stop latch (see FiGURE 4) is operated, the detent 1S3 stopping continued movement of the disc 15 by engaging the leading face of the projection 151A and the member 155 preventing any rebound movement. At the same time rocking of the lever 255 by the pin 282 about its pivot pin 257 causes the contacts of the microswitch 263 to open with consequent de-energisation of the auxi iary motor relay 265. The contacts 265A of the auxiliary motor relay 2&5 are, therefore, opened and the auxiliary motor 53 stops. The stopping position determined by the stop latch is arranged so that the needle of the sewing machine head is out of the workpiece.
Upon stopping of the auxiliary motor 53 the right foot pedal 199 is depressed thereby withdrawing the follower pin 29 of the cylindrical cam 21 from its associated cam track groove 23 and causing the foot of the sewing machine head to be raised off the workpiece. The frame holding the workpiece can then be removed and the car riage 11 can be repositioned manually in its extreme left position in which a further workpiece holding frame can be attached to the carriage.
In the event of an obstruction, for example, breaking of the needle 3 of the machine, arising during operation, the emergency switch 267 is placed in the emergency position to contact the terminal E. This causes de-energisation of the auxiliary motor relay coil 2&5, energisation of the emergency relay 2'73, closure of the contacts 273A in series with the coil of relay 273 and opening of the contacts 2738 in series with the contacts of the microswitch 189 associated with the second disc cam 1813. Both the auxiliary motor 53 and the clutch electromagnet 163 are therefore de-energised and the carriage ll of the apparatus is brought to rest and the obstruction can then be cleared The emergency switch is then restored to its normal position with the result that the auxiliary motor relay 265 is energised and sewing recommences under the influence or" the auxiliary motor 53. When it is observed tha operation is proceeding satisfactorily, the reset button 2'75 is pressed causing de-energisation of the emergency relay 273 and closure of the emergency relay contacts 2738 in series with the contacts of the microswitch 7.89 associated with the second disc cam 1813. The pressing of the reset switch button 275 causes energisation of the clutch control relay 277, depending upon the positions or" the latch levers A, 1858 and 185C of the three disc cams 181A, 1813 and 131C, either by way of the contacts of the microswitch 139 associated with the second disc cam 1813 or by way of the contacts of the microswitch 13? associated with the first disc cam 181A in series with the contacts 2733 of the emergency relay 273, which are biassed to closure thereof. It, upon pressing of the reset switch button 275 energisation of the clutch control relay 277 takes place by way of the contacts of the microswitch 137 associated with the first disc cam 181A and the contacts 273B of the emergency relay 273, it will be appreciated that upon energisation of the auxiliary motor relay coil 265 the contacts of the two-position contact 277A in series with the contacts of the microswitch 18''] associated with the first disc cam 181A are closed so that energisetion of the auxiliary mot-or relay coil 255 is maintained notwithstanding release of the reset push button 275.
The apparatus described enables sewing of a predetermined stitching line to be carried out in three stages, namely, a first stage in which sewing is conducted over an initial portion of the stitching line at a lower speed governed by the auxiliary motor 53, a second stage during which sewing of an intermediate portion of the stitching line is conducted at a higher speed governed by the main motor 51 of the apparatus, and a third stage in which a final portion or" the stitching line is conducted at the lower speed determined by the auxiliary motor 53.
Those skilled in the art will appreciate, however, that by providing the first and second disc cams 181A and 1813 with further peripheral recesses, sewing at the lower rate governed by the auxiliary motor 53 of a portion or portions of the stitching line other than the beginning and end thereof can be effected. Thus, for example, the invention renders feasible the attachment of an interiining ply to the plies of a one-piece collar without the use of loops at the points of the collar as described in United Kingdom patent specification No. 709,642. Also, the invention provides the possibility of applying the peripheral decorative stitching to a one-pi ce collar after the turning of the collar to bring the intcrlining thereof between the front and rear plies of the collar.
Further, by incorporating an electro-magnetic clutch in the drive from the motors 51 and 53 to the main shaft of the sewing machine head 1, for example, at the sprocket 5 or the sprocket 135, the further possibility is afforded of forming a predetermined line of stitching including a break, that is to say a section in which no stitches are made.
It has been found, moreover, that with the driving means of the present invention the speed at which stitching can be carried out under the influence of the main driving motor 51 can be increased. Also, sewing ripples at the commencement of stitching are avoided. Further, the invention enables stitching to be stopped precisely at the end of the stitching line with the needle out of the workpiece, so that no manual operation of the sewing machine needle by the operator of the apparatus is required. Breakages of thread caused by the sudden stopping of theapparatus at the end of thestitching line are also avoided.
With the advantages enumerated above the apparatus of the present invention facilitates mass production of articles for use in the garment industry, for example, shirt collars or cuffs, to be effected atia higher rate than has been the case hitherto.
I claim:
1. In a sewing machine of the type having an endwise reciprocable needle and having a workpiece supporting carriage mounted for motion in a plane substantially normal'to'the needle: 7 V
(A) a first power shaft rotatably driven at low speed;
(B) a second power shaft rotatably driven at higher speed; I
(C) a rotatable driven shaft;
(D) means comprising a clutch device for alternatively and selectively coupling the driven shaft with either the first or the second power shaft;
(E) carriage actuating means, drivingly connected with the driven shaft,'for moving the carriage;
(F) needle reciprocating means drivingly connected with the driven shaft;
(G) means comprising a manually operable actuator for causing the clutch device to couple the driven shaft with the first power shaft to initiate carriage movement and needle reciprocation at low speed; and
(H) a clutch control comprising means connected with the driven shaft to be responsive to the position of angular displacement thereof and operatively associated with the clutch device for causing the clutch device to couple the driven shaft with the second power shaft for high speed operation of the carriage and needle in consequence of apredetermined rotational displacement of the driven shaft at low speed.
2. In a sewingmachine of the type having, an endwise reciprocable needle and having a workpiece supporting carriage mounted for motion in a. plane substantially normal to the needle:
(A) a first power shaft rotatably driven at low speed;
(B) a second power shaft rotatably driven at higher a speed;
(C) a rotatable driven shaft;
(D) means comprising a clutch device for alternartively coupling the driven shaft with either the first or the second power shaft;
(E) needle reciprocating means connected with the driven shaft for moving the needle through a cycle of reciprocation each time the driven shaft is rotated through a predetermined angle of rotational dis placement;
(F) carriage actuating means, drivingly connected with the driven shafts for moving the carriage through a predetermined path in its said plane of motion each time the driven shaft undergoes a predetermined rotational displacement from a predetermined rotational position; and
(G) clutch control means responsive to rotational displacement of the driven shaft and operatively associated with the clutch device (1) for causing the clutch device to couple the driven shaft with the first power shaft at times 12 when :the driven shaft is rotatably displaced by certain angles from its said rotational position, and (2) for fcausing the clutch device to couple the driven shaft with the second power shaft at times when the driven shaft is in other positions of rotational displacement from its said rotational position. 7
3. The sewing machine of claim 2, further characterized by:
(A) detent brake-means releasably engageable with the driven shaft means for stopping the same in its said predetermined rotational position;
. (B) brake actuator means operatively associated with the detent brake means and responsive to rotational displaement of the driven shaft for engaging the detent brake means with the driven shaft whenever the driven shaft is brought to its said one rotational position; and
(C) manually operable means for effecting" release of the brake actuator means. I
4. The sewing machine of claim 2, further characterized by the fact that: the carriage actuating means comprises cam means rotatably driven by the driven shaft; and further characterized by the fact that the clutch control means comprises other cam means driven by the driven shaft for rotation in unison with said first designated cam ,means.
5. In a sewing machine having a lengthwise reciprocable needle and a workpiece supporting carriage mounted for motion in a plane normal to the needle and by which a workpiece can be carried under the needle to be stitched along a predetermined line:
(A) a first power shaft rotatably driven at a low speed;
(B) a second power shaft rotatably driven at a higher speed;
(C) a rotatable driven shaft;
(D) means including a clutch device for alternatively and selectively coupling the driven shaft with either the first or the second power shaft;
(E) camshaft means drivingly connected with the driven shaft for rotation at a speed which is in a predetermined ratio to the speed of the driven shaft;
(F) carriage actuating means drivingly connected with the driven shaft, for moving the carriage along the length of a predetermined path in its said plane of motion during each revolution of the camshaft means from a predetermined rotational position;
(G) cam means carried by the camshaft means for rotation in unison therewith;
(H) clutch control means comprising cam follower means cooperating with said cam means and operatively associated with the clutch device (1) for coupling the driven shaft with the first power shaft during movement of the cam shaft means through predetermined portions of each revolution thereof out of its said predetermined rotational position, and
(2) for coupling the driven shaft with the second power shaft during other portions of each revolution of the camshaft means;
(I) needle reciprocating means drivingly connected with the driven shaft;
(I) detent brake means releasably engageable with the driven shaft for stopping the same in a predetermined position of rotation at which the needle is 'raised;
' (K) brake actuator means comprising other can follower means cooperating with said cam means and operatively associated with said detent brake means for engaging the latter with the driven shaft when the camshaft means is in its said predetermined 'rotational position; and
- ('L)fi means for manually/releasing the detent brake means.
(References on foilowing page) References Cited in the file of this patent UNITED STATES PATENTS Knott July 30, 1946 De Vlieg et a1 July 24, 1951 Bihaly July 27, 1954 14 Bliedung et a1 Oct. 26, 1954 Von Zelewsky et al Apr. 30, 1957 Bihaly June 18, 1957 Breuer Jan. 12, 1960 Larys et a1 June 28, 1960

Claims (1)

1. IN A SEWING MACHINE OF THE TYPE HAVING AN ENDWISE RECIPROCABLE NEEDLE AND HAVING A WORKPIECE SUPPORTING CARRIAGE MOUNTED FOR MOTION IN A PLANE SUBSTANTIALLY NORMAL TO THE NEEDLE: (A) A FIRST POWER SHAFT ROTATABLY DRIVEN AT LOW SPEED; (B) A SECOND POWER SHAFT ROTATABLY DRIVEN AT HIGHER SPEED; (C) A ROTATABLE DRIVEN SHAFT; (D) MEANS COMPRISING A CLUTCH DEVICE FOR ALTERNATIVELY AND SELECTIVELY COUPLING THE DRIVEN SHAFT WITH EITHER THE FIRST OR THE SECOND POWER SHAFT; (E) CARRIAGE ACTUATING MEANS, DRIVINGLY CONNECTED WITH THE DRIVEN SHAFT, FOR MOVING THE CARRIAGE; (F) NEEDLE RECIPROCATING MEANS DRIVINGLY CONNECTED WITH THE DRIVEN SHAFT; (G) MEANS COMPRISING A MANUALLY OPERABLE ACTUATOR FOR CAUSING THE CLUTCH DEVICE TO COUPLE THE DRIVEN SHAFT WITH THE FIRST POWER SHAFT TO INITIATE CARRIAGE MOVEMENT AND NEEDLE RECIPROCATION AT LOW SPEED; AND (H) A CLUTCH CONTROL COMPRISING MEANS CONNECTED WITH THE DRIVEN SHAFT TO BE RESPONSIVE TO THE POSITION OF ANGULAR DISPLACEMENT THEREOF AND OPERATIVELY ASSOCIATED WITH THE CLUTCH DEVICE FOR CAUSING THE CLUTCH DEVICE TO COUPLE THE DRIVEN SHAFT WITH THE SECOND POWER SHAFT FOR HIGH SPEED OPERATION OF THE CARRIAGE AND NEEDLE IN CONSEQUENCE OF A PREDETERMINED ROTATIONAL DISPLACEMENT OF THE DRIVEN SHAFT AT LOW SPEED.
US71641A 1959-12-09 1960-11-25 Apparatus for guiding a workpiece under the needle of a sewing machine Expired - Lifetime US3079880A (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3224393A (en) * 1963-09-11 1965-12-21 Singer Co Automatically actuated sewing machines
US3448706A (en) * 1966-11-21 1969-06-10 Clark Co Inc David Variable repetitive pattern sewing machine
US3451366A (en) * 1967-06-30 1969-06-24 Sidney O Beck Tape monogrammer
US3492957A (en) * 1966-07-21 1970-02-03 Meca Meccanotecnica Cassanese Automatic stretch quilting machine
US3500778A (en) * 1969-01-30 1970-03-17 Gillette Co Automatic stretch quilting machines

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2404850A (en) * 1943-10-15 1946-07-30 United Shoe Machinery Corp Driving and stopping mechanism for sewing machines
US2561346A (en) * 1945-08-02 1951-07-24 Vlieg De Automatic positioning means for machine-tool supports and other supports
US2684651A (en) * 1949-12-20 1954-07-27 Bihaly Lajos Automatic guiding mechanism for sewing machines
US2692667A (en) * 1950-08-16 1954-10-26 Hansen Glove Corp Sewing machine needle control mechanism
US2790337A (en) * 1953-08-29 1957-04-30 Fischer Ag Georg Infinitely variable two-motor drive
US2796034A (en) * 1953-09-11 1957-06-18 Trubenised Company Sewing machines
US2920729A (en) * 1949-11-21 1960-01-12 Schloemann Ag Clutches for machine drives
US2942564A (en) * 1952-01-30 1960-06-28 Singer Mfg Co Needle positioning devices for sewing machines

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2404850A (en) * 1943-10-15 1946-07-30 United Shoe Machinery Corp Driving and stopping mechanism for sewing machines
US2561346A (en) * 1945-08-02 1951-07-24 Vlieg De Automatic positioning means for machine-tool supports and other supports
US2920729A (en) * 1949-11-21 1960-01-12 Schloemann Ag Clutches for machine drives
US2684651A (en) * 1949-12-20 1954-07-27 Bihaly Lajos Automatic guiding mechanism for sewing machines
US2692667A (en) * 1950-08-16 1954-10-26 Hansen Glove Corp Sewing machine needle control mechanism
US2942564A (en) * 1952-01-30 1960-06-28 Singer Mfg Co Needle positioning devices for sewing machines
US2790337A (en) * 1953-08-29 1957-04-30 Fischer Ag Georg Infinitely variable two-motor drive
US2796034A (en) * 1953-09-11 1957-06-18 Trubenised Company Sewing machines

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3224393A (en) * 1963-09-11 1965-12-21 Singer Co Automatically actuated sewing machines
US3492957A (en) * 1966-07-21 1970-02-03 Meca Meccanotecnica Cassanese Automatic stretch quilting machine
US3448706A (en) * 1966-11-21 1969-06-10 Clark Co Inc David Variable repetitive pattern sewing machine
US3451366A (en) * 1967-06-30 1969-06-24 Sidney O Beck Tape monogrammer
US3500778A (en) * 1969-01-30 1970-03-17 Gillette Co Automatic stretch quilting machines

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